The invention relates to a process for allowing pretreatment of components for an assembled camshaft in the course of whose production drive elements are attached in a force-locking way to a tube by plastic expansion of individual tube portions while exceeding the limit of elasticity of the material.
When producing assembled shafts, especially camshafts of the above mentioned type, it has been regarded as a special advantage that the drive element used, i.e. cams and drive elements, as well as bearing sleeves and possibly crank webs may be finish-machined prior to being connected hydraulically and that after producing the connection, the finished component is available. The tube material has to be selected as a function of the necessary different material properties of the various drive elements, with the relationship of yield points having to be taken into account to ensure that the limit of elasticity in the tube material is exceeded during expansion, whereas deformation in the material of the drive elements remains purely elastic, as otherwise the necessary force-locking connection cannot be produced. This limits the selection of materials, especially if cast cams are used which may crack if excessive elastic deformation through the expanded tube occurs. Furthermore, the tube material determined by the above conditions requires the application of separate bearing rings because the running properties of the untreated tube material are not always sufficient. Finally, it should be noted that the highly loaded connections for fixing driving pinions do not always meet the respective requirements.